feat: complete Phase 0 Enterprise IAM

src/db/migrations/postgres/0007_create_user_roles.sql

@@ -0,0 +1,7 @@
+CREATE TABLE IF NOT EXISTS user_roles (
+    user_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    role_id TEXT NOT NULL REFERENCES roles(id) ON DELETE CASCADE,
+    PRIMARY KEY (user_id, role_id)
+);
+
+CREATE INDEX IF NOT EXISTS idx_user_roles_user ON user_roles(user_id);